Remote indication system



B A. LANNGE REMOTE INDICATION SYSTEM Filed May 25, 1943 3 Sheets-Sheet l.Birger A H' Lonnge.

. INVENTQR 9M A T' Oct. 1, 1946. B. A.LANNGE 2,403,660

REMOTE INDICATION SYSTEM Filed May 25, 1943 l 5 Sheets-Sheet 2 llf '.5ir9er Ad 1 Lq g INVENTOR JZQAAT Y,

Patented Oct. 1, 1946 UNITED STATES PATENT OFFICE Application May 25,1943, Serial No. 488,393 In Sweden February 15, 1943 Claims. 1

The present invention relates to remote indication systems and moreparticularly to a circuit arrangement for indicating at a controlstation the occurrence, at any of a plurality of remote locations, of apredetermined physical condition.

One object of the invention is to provide a circuit arrangement of thistype for use on railroad trainsto operate an' alarm in the engineers cabas soon as a bearing begins to run hot and also to indicate the locationof the hot bearing.

Another object of the invention is to provide a remote indication systemof simple construction which is reliable in its operation andcomparatively simple to install.

A still further object of the invention is to provide an electricalalarm and indication system, in which the alarm mechanism is operatedwhen a normally established circuit is broken, whereas the indicator isnormally disconnected, but can be connected into an indicating circuitestablished upon the occurrence of a predetermined condition at a remotelocation.

These and other objects which will appear more fully as thespecification proceeds are accomplished, according to the presentinvention, by the arrangement and combination of elements, set forth inthe following detailed description, defined in the appended claims andillustratively exemplified in the accompanying drawings, in which:

Fig. l is a circuit diagram of one arrangement according to theinvention.

Figs. 2 and 3 are sectional views of a bimetal make after break contactdevice and of a fuse make after break contact device, respectively,which may be used in the arrangement according to Fig. 1.

Figs. 4 and 5 are partial diagrams of modified circuit arrangementsintended particularly for railroad trains.

Figs. 6 and- 7 are partial diagrams of circuit arrangements withmodified control stations.

Fig. 8 is a central sectional view of a; line coupling comprising twocoupling members in their connected positions.

Fig. 9 shows the right hand coupling member after it has beendisconnected from the left hand. member.

Figs. 10 and 11 are two sectional views taken online A--A in Fig. 9 andviewed in opposite directions, respectively.

In the arrangement shown in Fig. 1 which is particularly intended forstationary machinery, at number of thermally operated makeafter breakcontact devices I, described in more detail later on, are connected inseries in a bus line 2 which, at its" right hand end, is connected witha zero conductor 3. Shunt lines 4 extend from the zero conductor 3 inparallel to each of the contact devices I. The left hand end of the zeroconductor 3 is connected to one terminal of a battery 5. The otherterminal of the battery 5 is connected in parallel to a changeoverswitch 6 and, through the winding an of a relay 9, to the left hand endof the bus line 2. The change over switch 6- has two contacts 1 and 8.Contact l is connected with aback contact ll of the relay 9. The backcontact ll' cooperates with a stationary' contact connected through alamp [3 and a bell I4 with the first mentioned terminal of the battery5. The contact 8 of switch 6 is connected through an indicatinginstrument l5 with the bus line 2. Thecircuit' through coil 9a of therelay 9 is normally closed but will be broken in a manner explainedlater on when any one of the bearings reaches a critical temperature.When this happens, the' relay 9 is released and closes the contacts I I,[2 to complete a circuit from battery 5 through the lamp l3 and bell l4back to battery whereby the lamp is lighted and the bell is operated.Simultaneously, a spring actuated latch I0 is released and assumes aposition in which it prevents the armature of relay 9 from returning toits initial position even after the flow of current through its coil 9ahas been resumed.

In order to liberate the armature of relay 9, the latch to must bewithdrawn by means of the lower endof the manually controlled switchlever B cooperating with a projection on the latch l0 when the switch 6is changed over to close the contact 8. Thus, the latch l0, insurescontinuation of the alarm signal until the engineer operates switch 6 tochange over from contact I to contact 8. As a result of this operation,the relay 9 is liberated and the signal circuit through I3 and I4 isinterrupted so that the engineer is no longer troubled by the ringing ofthe bell l4; Simultaneously, the instrument [5 is connected into theline circuit to indicate the location of the hot hearing as explainedbelow;

The contact devices I, two embodiments of which are illustrated in Figs.2 and 3, are constructed in such a way that each device at a locationwhere a critical condition occurs, e. g. where the associated bearingreaches a critical temperature, first interrupts the bus line 2 at suchlocation. and, immediately thereafter, conneot's the associated shuntline 4 with that part of the bus line 2, which in Fig. l is disposed tothe left of the location in question. As a result, the circuit includingthe instrument I5 is closed through all the contact devices I which, inFig. l, are to the left of the hot bearing. The bus line 2 may consistof wire of relatively high resistance and may be so arranged that theresistances between successive contact devices I are equal.Alternatively,.the line may consist of low resistance Wire and haveequal ohmic resistances connected therein between successive contactdevices i. In either case, the instrument I5 will operate in function ofthe magnitude of the resistance of the part of the bus line 2 disposedin Fig. 1 to the left of the hot bearing. As will be clear, theinstrument may be graduated to indicate directly the location of the hotbearing.

Each contact device I connected, for example as shown in Fig. 2. Thecontact device shown in this figure comprises a casing I6 provided withan external screw thread I! to be screwed into a threaded bore in thebearing to be controlled. The associated shunt line 4 and the part ofbus'line 2 to the right of each contact device I (as shown in Fig. 1)are connected to two contacts I8 and [9, respectively, while the part ofbus line 2 to the left of each contact device I as shown in Fig. 1 isconnected to a contact spring 20. The contact spring is controlled by abimetal bar 2| fixed in the casing I5. In cold condition, the bimetalbar I6 assumes a bent position, as shown in full lines in Fig. 2, thuskeeping the contact spring 2!) in touch with the contact I9 so that thetwo parts of bus line 2 are normally series connected with each other.However, when the bearing reaches its critical temperature, the bimetalbar straightens, as shown in dotted lines in Fig. 2 and the contact I9,20 is broken so that the line current is interrupted and the relay 9 isreleased. Shortly thereafter, the contact spring is caused to touch thecontact I8 so that the zero conductor is connected through theassociated shunt line 4 with the part of bus line 2 which extends to theleft of the operating contact device I in Fig. l. The instrument I5 maynow'be connected into this circuit to indicate the location of thebearing which is running hot.

In the modified contact device shown in Fig. 3, a hollow plug 22, madefor example of ceramic or Bakelite, is screwed into the casing It. Theterminals of lines 2 and 4 pass through bores provided in the plug 22.An easily fusible metal 23 is cast into the plug 22 and surrounds bothterminals of the bus line 2 without reaching the exposed terminal of theshunt line 4. When the bearing becomes hot, the metal 23 fuses andbreaks the contact between the two terminals of the bus line 2. Shortlythereafter. the molten metal established contact between the terminalleading to the part of the bus line 2 extending to the left of thecontact device I in Fig. 1 and the terminal of the shunt 4 leading tothe zero conductor 3.

Figs. 4 and 5 show circuits which are particularly intended for railroadtrains. These circuits comprise two bus lines 24, into which the contactdevices I are connected in series and either one (Fig. 4) or two (Fig.5) zero conductors 26. The shunt lines 4 extend from said zero conductoror conductors 26 to the contact devices I in the bus lines 24, 25. Thetwo pairs of contact devices I shown in the left hand part of each ofFigs. 4 and 5 belong to the bearings of one carriage. All the lines 24,25 and 26 passmay be formed and ing through this carriage are connectedto the corresponding lines in an adjacent carriage, indicated in theright hand part of Figs. 4 and 5, by

means of diagrammatically shown couplings 21. 5 The arrangement maycomprise three wires (Fig. 4) or four wires (Fig. 5) In the case of athree line arrangement, the wires are, preferably, disposedapproximately centrally under the carriage and follow, for example, thecompressed air brake line. The shunt lines 4 run along the axles to therespective bearing bushes on both sides of the carriage. The zeroconductor 25 runs without interruption throughout the length of thecarriage and is connected by the shunt lines 4 to the individual contactdevices I, respectively.

In an arrangement comprising two bus lines 24, 25 and two zeroconductors 26, the four wire line may either run centrally under thecarrings or, as shown in Fig. 5, it may be branched in such a way thatone bus line 24 or 25 and one Zero conductor 26 extend along eachcarriage side immediately above the bearing bushes. The lines 24, 25 and25 are combined into a common flexible cable at each carriage end wherethey terminate in a suitable coupling piece.

One embodiment of a coupling which may be used in connecting thecircuits of successive railroad carriages in a system according to thepresent invention is shown in Figs. 8 to 11. The coupling illustrated inFig. 8 comprises two similar coupling members 2M and 212). Each couplingmember consists of an insulating casing 28 having mounted therein andprojecting therefrom an insulating plug 29 on which a plurality ofcontact bars 33a, 30b, and 300 are located side by side but insulatedfrom one another, as shown in Fig. 11. Each contact bar 36a, 30b, Silois connected with a contact spring SIa, 3|b, and 3lc, respectively, andeach contact bar with its appertaining contact spring is connected toone of the lines running through the train. As exemplified in Fig. 11,bar 30a and spring 3Ia are connected to the bus line 24 (see Fig. 3),contact bar 301) and spring 3Ib are connected to the zero conductor 25,and bar (Illc and spring 3Ic are connected to the bus line 25. Withineach casing 28 there is further provided a metal spring plate 32 withwhich, is disconnected condition of the member 21a or 2112 all thecontact springs 3Ia, 3Ib and die make contact (see Fig. 9). Whencoupling is to be effected, the insulating plug 29 of each couplingmember 21a and 21b is inserted between the contact springs 3Ia, 3Ib, Moand the spring plate 32 of the other members 211) and 21a, so that, ineach member, the connection between the spring 31a, 3Ib and 3Ic by meansof the spring plate 32 is broken and each contact bar 30a, 30b and 300of each coupling member 21a and 21b is separately connected with thecorreo spending contact springs 3Ia, 3Ib and 3Ic of the other couplingmembers 21b and 27a. Thus a through connection between the correspondingbus lines and zero conductors from carriage to carriage is established.

Figs. 6 and '7 show diagrammatically different embodiments of theinstruments at the control station of the device and also modifiedconnections of the lines to said control station.

According to Fig. 6, the line system corresponds to that shown in Fig.3, i. e. it comprises three wires including two bus lines 24, 25 and acommon zero conductor 25. Contact devices I are connected serially intothe bus lines 24 and 25 in the manner shown in Figs. 1 to 3. Each wireis connected with two terminal contacts arranged for cooperation with achange over switch 33 having its two arms connected to two terminals ofthe control station, respectively. The control station comprises aresistance measuring instrument, such as a galvanometer, l5, which is sograduated that each line represents a certain bearing on the train.Thus, when the switch 33 is set to its proper position, the engineer candirectly see which bearing is running hot.

In the circuit connection of the control station according to Fig. 6,the lamp I3 is normally lighted, but becomes extinguished when a bearlngbegins to run hot, as the circuit through the lamp includes both buslines 24, 25, normally connected in series by the change over switch 33set to the position 0, as shown in the drawings. When this circuit isbroken in one of the contact devices I, the relay 9 connected inparallel with lamp l3 across the battery 5 through the seriallyconnected bus lines 24, 25 releases and the bell mechanism I4 isenergized over the back contact ll of relay 9, as in Fig. 1. Normally,the switch 6 is set to the position shown and the change over switch 33is set to the position 0. Current then flows from one terminal of thebattery 5 through the relay winding 9a, and parallel, thereto, overswitch 6, contact 1 and front contact I la of relay 9 through lamp l3 tothe lower contact arm of switch 33, thence over contacts C, A throughbus line 25 to the end of the train, and back through bus line 24 overcontacts B, C and the upper contact arm ofswitch 33 to the secondterminal of the battery 5. When a bearing begins to run hot and breakcontact (e. g. I9, in Fig. 2) is caused to operate, the lamp I3 isextinguished and the relay 9 releases and connects the bell mechanism l4into a circuit extending from the first terminal of battery 5 overswitch 6, contact 1, back contact ll of relay 9 and through the bellmechanism I4 to the other terminal of battery 5.

The engineer, then, operates the switch 6 to connect the first terminalof the battery 5 through switch 6 and contact 8 to one terminal of thegalvanometer l5. Simultaneously, the lamp and bell circuits are bothbroken at contact l of switch 6. Next, the change-over switch 33 is setto the position A to test the left side of the train and subsequently toposition B to test the right side of the train. When the switch 33 is inposition A the circuit through the galvanometer I5 is closed through thelower arm of 33, contact A, bus line 25, zero conductor 26 connected tothe bus line either at the end of the train or at the location of thehot bearing, contact A and upper arm of the switch 33 to the secondterminal of battery 5. With switch 33 in position B the circuit throughthe galvanometer I5 is closed through the lower arm of switch 33,contacts B, A, zero conductor 26, bus line 24 connected to the zeroconductor 26 either at the end of the train or at the location of thehot bearing, contact B and upper arm of switch 33 to the second terminalof the battery 5. The hot bearing is found in the line for which thegalvanometer [5 displays the smaller deflection, and the magnitude ofsuch smaller deflection indicates which bearing is running hot countedfrom the locomotive. If, in the arrangement according to Fig. 6, theswitch 33 is set to either its position A or its position B while theswitch 6 is in its position closing its contact 'I, the circuit throughthe winding 9a of relay 9 would immediately be closed over the zeroconductor 26, but due to the latch H], the relay 9 would be preventedfrom attracting its armature so that the circuit through the bell Iwould not be broken and the circuit through the lamp I3 which includes afront contact Ila of the relay 9 could not be reestablished until afterthe switch 6 has first been moved to its right hand position and has,then, been returned to its original position.

Fig. '7 shows a four wire system corresponding to that illustrated inFig. 4, with two bus lines 24, 25 and two zero conductors 26. Aresistance measuring apparatus constructed in the form of a Wheatstonebridge is provided at the control station. Normally, the current flowsfrom the battery 5 through the relay winding 9a and the change-overswitch 33 in the illustrated position C1 and hence, through the two busline 25, 26 in series back to the battery.

After an alarm has been given due to the operation of a contact deviceI, and the switch 6 has been operated, the change-over switch 33 is setsuccessively from its normal position C1 to the test positions A and B.In either test position of the switch 33, the rheostat 34 is turneduntil the galvanomete'r l5 indicates 0, whereby, as known, the bridgebranch resistances r1, r2, r; and m are related to one another asfollows: r1/r2=r3/r4. n represents the resistance of the train line. Thepointer of the rheostat 34 now indicates which bearing is running hot.Three or more ohmic resistances R1, R2, R3 having different values areadapted to be connected into the bridge branch T2 in order to limit thesize of the rheostat, said resistances being dimensioned in such a waythat the same rheostat can be used for trains of different lengths. R1may be connected in the case of short trains, B2 in the case of longertrains and R3 in the of particularly long trains, such as long freighttrains. The rheostat 34 is provided with three different scales,corresponding to R1, R2, and R3 to permit proper readings whicheverresistance R be connected in the circuit.

By line wires which have a certain known self-resistance per bearingdistance, or by providing a wire system with small self-resistance andproperly dimensioned ohmic resistances connected at each bearing, theindication can he made very reliable and easily readable so that theengineer can ascertain immediately the location of any hot hearing.

If due to a hot bearing one bus line been broken, it is possible tomaintain the other bus line in operative condition by means of anemergency switching, Thus, if for instance, the left bus line 25 hasbeen interrupted due to the hot running of a bearing along this line,the changeover switch 33 may be set to the position B so that an alarmsignal may be received from any contact device I in bus line 24 and thelocation of any hot bearing on the right side of the train may then beascertained as soon as the switch 6 has been set to its right handposition. Similar emergency switching can be used in arrangementscomprising three instead of four wire lines.

If, with the change-over switch 33 in the position Cl, the connectionbetween two cars of the train breaks so that the coupling members 21a,21b (see Figs. 8 to 11) are disconnected from each other, the circuitthrough bus lines 24, 25 is first broken and, immediately thereafter,the bus lines 24, 25 and the zero conductor or conductors 23 at the endof the last carriage left on the train are automatically connectedtogether in the terminal coupling member 21a or 211) as explained abovein connection with Figs. 8 to 11. Due to momentary line interruptionthus caused, the relay 9 is released and the alarm is started. When theengineer tests the lines, he will find that the deflection of thegalvanometer needle is the same in position A and in position B of thechange-over switch 33, thus indicating that the alarm is due to the lossof a part of the train and not to a hot bearing.

In the device according to Fig. 7, the changeover switch 33 may also beset to a fourth p'osi tion C2 to connect the two zero conductors 26 inseries across th alarm starting relay 9. This makes it possible toprovide for an operation of the alarm devices upon loss of any part ofthe train even after both bus lines 24 and 25 have been broken by hotrunning bearings.

It is possible to substitute ground for the zero conductor in thesystems according to the invention. In such a case, only the bus linesrun underneath the carriages, and when a bearing runs hot the contactdevice at the location of such bearing breaks the bus line and connectseither only that part of the bus line which runs forward to the engineor both parts of the bus line to ground. One terminal of the controlstation in the engine is also connected to ground so that either one ortwo measurable circuits are obtained, which inform the engineer on whichside of the train a bearing is running hot and where such bearing islocated. However, since ground is not a reliable conductor and has arather high resistance, the bus lines must, in this case, be given anextraordinarily high self-resistance in order to obtain a reliabledeflection.

The alarm system according to the invention can also be used instationary lants. For instance in a plant in which a number of bearingsare disposed in positions which are difficult to control, lines may beconnected to said bearings in a predetermined succession withpredetermined resistances interposed between the serially arrangedcontact devices associated with the individual bearings, respectively.

The lines end in a control station located at the place of the plantguard, from which place the whole plant can be supervised andcontrolled.

Having now described my invention, what I claim as new and desire tosecure by Letters Patent is:

1. In an arrangement for indicating at a control station the occurrence,at any one of a plurality of remote locations, of a predeterminedphysical condition, the combination of an alarm mechanism at saidcontrol station including a relay, an alarm device, an energizingcircuit for said alarm device including a back contact of said relay,and means operative upon release of said relay for locking said backcontact in closed position, a source of current connected in series withsaid relay, a. contact device at each location including a normallyclosed contact adapted to open upon occurrence of said predeterminedphysical condition at its location and a normally open contact adaptedto close shortly after the opening of the associated normally closedcontact, said normally closed contacts being connected in series acrosssaid source of current and relay to keep the latter normally energized,circuits connecting said normally open contacts parallel to each otheracross said relay and source of current, each of said circuits having apredetermined resistance different from those of all the other parallelcircuits, a normally open shunt across said relay, an electricalmeasuring instrument in said shunt, and an operator controlled switch toclose said shunt.

2. A combination, as claimed in claim 1, including coupling meansbetween said operator controlled switch and said back contact lockingmeans to effect unlocking of said back contact when said switch ischanged over to close said shunt.

3. A combination, as claimed in claim 1, including a normally closedcontact in the energizing circuit of said alarm device said contactbeing opened when said switch is changed over to close said shunt.

4. A combination, as claimed in claim 1, in which the circuitsconnecting said con-tact devices across said relay and source of currentinclude at last one bus line connecting a number of said normally closedcontacts in series to one terminal of the source of current and at leastone zero conductor leading from the last closed contact of said seriesto the other terminal of said source, each normally open contact havingone contact element connected to the art of the bus line extendingbetween the location of this contact and said first terminal of thesource of current and a second contact element shunt connected to saidzero conductor.

5. A combination, as claimed in claim 1, in which the normally closedcontacts are series connected into two bus lines and at least one commonzero conductor is connected to the last normally closed contact of eachseries, each normally open contact including one contact element whichis shunt connected to a zero conductor, and a change over switch forconnecting said source of current and relay alternatively across bothbus lines or across either bus line and a zero conductor.

BIRGER ADOLI? LANNGF-

